Danfoss D9h Operating Manual page 147

VLT® AutomationDrive FC 302
Operating Guide
9.4.26 WARNING/ALARM 27, Brake Chopper Fault
Cause
The brake transistor is monitored during operation, and if a short circuit occurs, the brake function is disabled, and a warning is
issued. The drive is still operational, but since the brake transistor has short-circuited, substantial power is transmitted to the brake
resistor, even if it is inactive.
Troubleshooting
• Remove the power to the drive and remove the brake resistor.
9.4.27 WARNING/ALARM 28, Brake Check Failed
Cause
The brake resistor is not connected or not working.
Troubleshooting
•
Check parameter 2-15 Brake Check.
9.4.28 ALARM 29, Heat Sink Temp
Cause
The maximum temperature of the heat sink is exceeded. The temperature fault is not reset until the temperature drops below a
defined heat sink temperature. The trip and reset points are different based on the drive power size.
Troubleshooting
Check for the following conditions:
• The ambient temperature is too high.
• The motor cables are too long.
• Incorrect airflow clearance above and below the drive.
• Blocked airflow around the drive.
• Damaged heat sink fan.
• Dirty heat sink.
9.4.29 ALARM 30, Motor Phase U Missing
Cause
Motor phase U between the drive and the motor is missing.
Troubleshooting
• Disconnect power before proceeding.
• Remove the power from the drive and check motor phase U.
9.4.30 ALARM 31, Motor Phase V Missing
Cause
Motor phase V between the drive and the motor is missing.
Troubleshooting
• Disconnect power before proceeding.
• Remove the power from the drive and check motor phase V.
9.4.31 ALARM 32, Motor Phase W Missing
Cause
Motor phase W between the drive and the motor is missing.
Troubleshooting
• Disconnect power before proceeding.
• Remove the power from the drive and check motor phase W.
Danfoss A/S © 2021.10
Maintenance, Diagnostics, and
Troubleshooting
AQ262139143212en-000301 / 130R0879 | 147